Cable duct coupler

ABSTRACT

A cable duct coupler for coupling a first cable duct section to a second cable duct section without the need for tools, the cable duct coupler comprising a channel portion, a first outer guide element and a second outer guide element, a barb mount extending from at least one of the channel portion and the outer guide elements, and a barb having a body and first and second arms extending from the body, the barb being mounted on the barb mount, wherein at least a portion of the first arm extends at an angle between the first portion of the channel portion and the barb body and at least a portion of the second arm extends at an angle between the second portion of the channel portion and the barb body.

RELATED APPLICATION

This application is a continuation, claiming priority to previouslyfiled U.S. patent application Ser. No. 10/323,527, filed on Dec. 18,2002, now U.S. Pat. No. 6,634,605, which is a continuation, claimingpriority to previously filed U.S. patent application Ser. No.10/039,325, filed on Oct. 27, 2001, now U.S. Pat. No. 6,523,791, whichis a continuation-in-part application, claiming priority to previouslyfiled U.S. patent application Ser. No. 09/585,699, filed on Jun. 1,2000, now U.S. Pat. No. 6,450,458, the entirety of the previously filedapplications being incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

Raceway duct systems have become very popular in recent years to route,protect, and conceal data, voice, video, fiber optic and/or powercabling. Such systems allow custom installation and can be providedwithin walls or more preferably provided on external surfaces, allowingready access for reconfiguration, repair, or installation of additionalequipment. Such systems may typically include various sections of ductor raceway, including straight sections and various fittings, such as90° elbow fittings, 45° elbow fittings, T-fittings, four-wayintersection (x) fittings, and the like, respective ones of which areaffixed together by duct couplers to cumulatively form a duct system.

Due to the increase in number and sophistication of such raceway ductsystems, the number of duct couplers being installed in such systems hasalso increased significantly. Therefore, it is important to havecouplers that are easy to install and expensive to manufacture, and thatprovide relatively high pull-out force to prevent unintendeddisassembly.

SUMMARY OF THE INVENTION

In one form of the invention, there is provided a cable duct coupler forcoupling a first cable duct section to a second cable duct sectionwithout the need for tools, the first and second cable duct sectionseach having an end, the cable duct coupler comprising a channel portionhaving a first portion generally complementary to the end of the firstcable duct section and a second portion generally complementary to theend of the second cable duct section, a first outer guide elementgenerally complementary to the end of the first cable duct section and asecond outer guide element generally complementary to the end of thesecond cable duct section, wherein the end of the first cable ductsection is receivable into the coupler between the first portion of thechannel portion and the first outer guide element and the end of thesecond cable duct section is receivable into the coupler between thesecond portion of the channel portion and the second outer guideelement, a barb mount extending from at least one of the channel portionand the outer guide elements, and a barb having a body and first andsecond arms extending from the body, the barb being mounted on the barbmount, wherein at least a portion of the first arm extends at an anglebetween the first portion of the channel portion and the barb body andat least a portion of the second arm extends at an angle between thesecond portion of the channel portion and the barb body, wherein uponinsertion of the end of the first cable duct section into the couplerbetween the first portion of the channel portion and the first outerguide element, the first arm of the barb engages the first cable ductsection to significantly resist withdrawal of the first cable ductsection, and wherein upon insertion of the end of the second cable ductsection into the coupler between the second portion of the channelportion and the second outer guide element, the second arm of the barbengages the second cable duct section to significantly resist withdrawalof the second cable duct section.

In another form of the invention, there is provided a cable duct systemcomprising a first cable duct section having an end, a second cable ductsection having an end, and a cable duct coupler including, a channelportion having a first portion generally complementary to the end of thefirst cable duct section and a second portion generally complementary tothe end of the second cable duct section, a first outer guide elementgenerally complementary to the end of the first cable duct section and asecond outer guide element generally complementary to the end of thesecond cable duct section, wherein the end of the first cable ductsection is receivable into the coupler between the first portion of thechannel portion and the first outer guide element and the end of thesecond cable duct section is receivable into the coupler between thesecond portion of the channel portion and the second outer guideelement, a barb mount extending from at least one of the channel portionand the outer guide elements, and a barb having a body and first andsecond arms extending from the body, the barb being mounted on the barbmount, wherein at least a portion of the first arm extends at an anglebetween the first portion of the channel portion and the barb body andat least a portion of the second arm extends at an angle between thesecond portion of the channel portion and the barb body, wherein uponinsertion of the end of the first cable duct section into the couplerbetween the first portion of the channel portion and the first outerguide element, the first arm of the barb engages the first cable ductsection to significantly resist withdrawal of the first cable ductsection, and wherein upon insertion of the end of the second cable ductsection into the coupler between the second portion of the channelportion and the second outer guide element, the second arm of the barbengages the second cable duct section to significantly resist withdrawalof the second cable duct section.

In yet another embodiment of the invention, there is provided a methodfor assembling a cable duct system, the method comprising providing afirst cable duct section having an end, providing a second cable ductsection having an end, providing a cable duct coupler having a channelportion with a first portion generally complementary to the end of thefirst cable duct section and a second portion generally complementary tothe end of the second cable duct section, a first outer guide elementgenerally complementary to the end of the first cable duct section and asecond outer guide element generally complementary to the end of thesecond cable duct section, a barb mount extending from at least one ofthe channel portion and the outer guide elements, and a barb having abody and first and second arms extending from the body, the barb beingmounted on the barb mount, wherein at least a portion of the first armextends at an angle between the first portion of the channel portion andthe barb body and at least a portion of the second arm extends at anangle between the second portion of the channel portion and the barbbody, inserting the end of the first cable duct section between thefirst portion of the channel portion and the first outer guide elementuntil the first arm of the barb engages the first cable duct section tosignificantly resist withdrawal of the first cable duct section, andinserting the end of the second cable duct section between the secondportion of the channel portion and the second outer guide element untilthe second arm of the barb engages the second cable duct section tosignificantly resist withdrawal of the second cable duct section.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cable duct coupler and cable ductsystem in accordance with an embodiment of the invention wherein firstand second cable duct sections are coupled together by the coupler;

FIG. 2 is a perspective view of the coupler of FIG. 1;

FIG. 3 is a front elevational view of the coupler of FIG. 1;

FIG. 4 is a partially exploded perspective view of the duct sectioncoupler of FIG. 1 showing the alignment of an end of the cable ductsection with the coupler and the alignment of the barb, cover, and screwto the coupler body;

FIG. 5 is a cross-sectional view of the coupler of FIG. 1 showing thebarb thereof in detail, the cross-sectional view taken across the line5-5 in FIG. 1;

FIG. 6 is a perspective view of an alternative embodiment of the barb;

FIG. 7 is a reverse perspective view of the barb of FIG. 6; and

FIGS. 8-15 show various cable duct system fittings, with lids, that maybe coupled to each other or to a cable duct section by a coupler inaccordance with the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a cable duct system 10 in accordance with an embodiment ofthe invention, and in particular shows a pair of discrete cable ductsections 12 each having an end 13 (FIG. 4) inserted into and retained bya cable duct coupler 20 in accordance with an embodiment of theinvention. As seen, the end of the cable duct section preferably has aU-shape, with a bottom portion 14 and two upwardly extending sideportions 16. The bottom portion may preferably include axially extendingribs 18 for strengthening the cable duct section, for facilitating themounting of the cable duct section onto a floor, wall, bracket, or othersupportive structure, and for preferably providing alignment criteriarelative to the coupler 20. At or near the distal ends of the sideportions 16, there may also preferably be a curved lip 19 or the likefor facilitating the attachment of a lid over the cable duct section 12to substantially enclose the cable duct section and retain one or morecables therein, as is well known in the art. The duct section may alsoinclude longitudinal ribs 17 on the outside thereof. The cable ductsection is preferably made from a hard plastic or other strong, slightlydeformable, dielectric material.

The coupler 20 is shown in greater detail in FIGS. 2 and 3, with FIG. 2showing the coupler in perspective and FIG. 3 showing a frontelevational view thereof. The coupler 20, as seen previously in FIG. 1,joins two discrete cable duct sections 12, and the coupler has an axialdirection generally in accordance with and parallel to the direction inwhich cables will generally lie as they pass through the coupler, i.e.,generally in line with the longitudinal direction of the cable ductsections.

Coupler 20 has a channel portion 22 which defines the cable pathwaytherethrough as the cable makes its way from one cable duct section toanother. In a preferred embodiment, the channel portion includes abottom portion 30 and two side portions 32 extending somewhatperpendicularly to each end of the bottom portion 30. The side portions32, in a preferred embodiment, form a slightly obtuse angle (>90°)relative to the bottom portion 30, to open the section and facilitatecable retention and withdrawal. The channel portion 22 has an innersurface 26 including the facing surfaces of the side portions 32 and theupper surface of the bottom portion 30, and an outer surface 27including the opposite surfaces of the bottom and side portions 30 and32.

In a preferred embodiment, the coupler includes a rib 36 extendingoutwardly and generally perpendicularly from the outer surface 27 of thechannel portion 22. The rib 36 preferably completely traverses the outersurface 27 of the channel portion 22, dividing it and the entire couplerinto two symmetric halves, a first portion 24 for receiving a firstcable duct section and a second portion 25 for receiving a second cableduct section. In a preferred embodiment, the rib 36 is centrallydisposed along a line of symmetry for the coupler. As seen in FIGS. 2and 3, the outer surface 27 of the channel portion 22 may preferablyinclude contact ridges 28 for contacting and facilitating the alignmentof an end of a cable duct section when inserted into the coupler.

Coupler 20 also includes a number of outer guide elements facilitatingthe alignment of a duct section end as it is inserted into the coupler.In the illustrated embodiment, the coupler includes a pair of outerguide elements 40 disposed opposite the outer surface 27 of the bottomportion 30 of the channel portion 22, and a pair of outer guide elements42 opposing the outer surface 27 of each side portion 32 of the channelportion 22. The outer guide elements 40 include guide surfaces 44 andaxial web portions 48, with the guide surfaces 44 and axial web portions48 being supported by a centered transverse web portion 50, all of whichextend from the narrow central rib 36 traversing the outer surface 27 ofthe channel portion 22. The outer guide elements 42 opposite the sideportions 32 of the channel portion also include guide surfaces 44 andaxial web portions 48, but they are supported by a pair of non-centrallydisposed transverse web portions 52 extending outwardly from thecorresponding guide surfaces 44. Any or all of the guide surfaces 44 ofthe respective outer guide elements 40 and 42 may preferably includealignment ridges 46 for contacting and facilitating the alignment of anend of a cable duct section being inserted into the coupler.Additionally, there may be any number of guide elements 40 and 42 withinthe scope of the invention, and the gaps 49 between adjacent guideelements may, in particular embodiments of the invention, be spanned bya strengthening web 53 to strengthen the coupler generally.

In the illustrated embodiment of the invention, and as best seen inFIGS. 2 and 4, between particular outer guide elements, 40 and 42, thereare gaps 49. Preferably disposed between transverse web portions 50 and52 corresponding to adjacent outer guide elements 40 and 42, andpreferably disposed on or substantially on the central rib 36, there isa barb mount 60 for receiving a fastener therein. In the illustratedembodiment, the barb mount supports a barb 54 thereon and has aninternally threaded aperture 78 therein. As seen in FIGS. 4 and 5, thebarb 54 includes a pair of arms 64 bent back relative to a body portion62 at an angle greater than 90 degree so that the arms angle towardseach other. The barb body 62 is mountable upon the barb mount 60 andretainable thereon by an externally threaded screw 58 or other fastenerwhich penetrates a hole 56 in the barb and is directed into theinternally threaded screw aperture 78 in the barb mount 60. Externallythreaded screw 58 or other fastener may also serve as a releasemechanism adapted to release barbs 54 from retaining a first cable ductsection positioned within a first duct-receiving portion of coupler 20.Thus, the barbs 54 are mounted in gaps 49 between particular outer guideelements 40 and 42. In a preferred embodiment of the invention, the barbmay have serrated edges 66 at the distal ends of its arms 64. Theserrated edges permit the barb arms to more reliably engage insertedcable duct sections so as to resist withdrawal of the section from thecoupler. In particular, the serrated edge may “bite” or “dig” into thematerial of the duct section 12, such as extruded plastic.

Also in a preferred embodiment of the invention, and as best seen inFIGS. 6 and 7, the barb body 62 may have one or more flanges 68 runninglengthwise along the edges thereof. Such flanges render the barb body 62less prone to bending/deflection during withdrawal of a duct sectionfrom the coupler and thereby increase the minimum withdrawal force ofthe coupler. Also in a preferred embodiment of the invention, portionsof the barb arms 64 and portions of the barb body 62 include one or moreribs 70 to strengthen the barb and make it less vulnerable to having thebarb arm 64 deflected relative to the barb body 62, especially duringduct section withdrawal. Also in a preferred embodiment of theinvention, the barb cover 72 may include a hole centrally locatedtherein so that it may be retained over the barb body by the screw 58.Covers 72 enhances the aesthetic appearance of the coupler by hiding themetal barbs 54 and, in some embodiments, may provide contact support forthe barbs 54 when withdrawal force is applied to a cable duct sectioninserted into the coupler.

When the end 13 of a cable duct section 12 is to be inserted into acoupler 20 in the illustrated embodiment of the invention, the U-shapedprofile of the end 13 is inserted to generally circumscribe the outersurface 27 of the channel portion 22 of the coupler. The various guidesurfaces 44 of the outer guide elements 40 and 42 may initially contactthe end 13 of the cable duct section 12 and facilitate alignment of thecable duct section into the coupler. In particular, contact ridges 46 ofthe guide surfaces 44 assist in the alignment upon insertion, as do thecontact ridges 28 on the outer surface 27 of the channel portion 22. Thecable duct section's strengthening ribs 18 are aligned to fit into gapsbetween the outer guide elements 40, 42.

While the end 13 of the cable duct section 12 approaches its fullyinserted position adjacent to the central rib 36, it encounters barbarms 64 angled generally in the direction of the insertion. Because theend 13 lacks sufficient clearance, it will contact one of each barb'sarms 64 upon insertion. The barb arms 64 will deflect slightly towardtheir respective barb bodies 62 to permit the end 13 to pass thereunderwithout offering substantial resistance as the end continues toward thecentral rib 36. The serrated edges 66 of the barb arms 64 will notsignificantly bite into the extruded plastic end 13 during insertion dueto the angle of the barb arms 64. Once the end 13 comes flush with thecentral rib 36, the insertion is completed.

When a withdrawal force is applied to the cable duct section 12, the end13 of the cable duct section begins to and nominally slides away fromthe central rib 36, but upon such nominal movement in the withdrawaldirection, the serrated edges 66 of the barb arms 64 bitingly engage anddig in to the extruded plastic of the duct section 12. Longitudinal ribs17 on the exterior of the duct section are optionally provided toenhance the magnitude of engagement of the barb arms 64 therewith. Thewithdrawal forces are thereby countered by the resistance of the barbarms 64 to open. Thus, in order to withdraw the cable duct section,enough withdrawal force must be applied to either significantly deformthe arms of the barbs or to permit the serrated edges 66 of the barbarms 64 to lose their biting grip thereon and thereby score the cableduct section 12 as it is withdrawn from the coupler. In a preferredembodiment of the invention, the duct section slides under the barb arm,with possible socring, and the barb arms are not permanently deformedwhen a withdrawal force exceeding the minimum withdrawal force isapplied to the duct section. Avoiding damage to the barb arms permitsthe coupler to be reused.

In the embodiments of the invention including a barb cover, such as barbcover 72, the cover may prevent or limit deflection of the barb body ina direction away from the cable duct section so as to support themagnitude of biting engagement between the serrated edge 66 and theextruded duct section. In the embodiments shown in FIGS. 6 and 7, theflange(s) 68 and the rib(s) 70 provide the support without the presenceof a barb cover.

FIGS. 8-15 show various cable duct system fittings, with lids, that maybe coupled to each other or to a straight cable duct section by acoupler in accordance with the invention. FIG. 8 shows an outsidevertical right angle fitting for routing cable between a horizontalorientation and a vertical orientation. FIG. 9, similarly, shows anoutside vertical 45° fitting. FIG. 10 shows an inside vertical 45°fitting. FIG. 11 shows an inside vertical right angle fitting. FIG. 12shows a four-way cross fitting. FIG. 13 shows an inside vertical rightangle fitting. FIG. 14 shows a horizontal Tee fitting. FIG. 15 shows avertical Tee fitting. These fittings are exemplary and in no way limitthe scope of the application of the inventive cable duct system andcoupler.

The disclosed invention provides an improved cable duct coupler andcable duct system. It should be noted that the above-described andillustrated embodiments and preferred embodiments of the invention arenot an exhaustive listing of the forms such a coupler and system inaccordance with the invention might take; rather, they serve asexemplary and illustrative of embodiments of the invention as presentlyunderstood. By way of example, and without limitation, a non-U-shapedcoupler and correspondingly shaped duct sections are contemplated to bewithin the scope of the invention. Similarly, while the illustratedembodiment includes covers over each of the barbs in the coupler,embodiments having no covers are also contemplated by the invention.Many other forms of the invention are believed to exist. The inventionis defined by the following claims.

1. A cable duct coupler for coupling a first cable duct section to asecond cable duct section, said cable duct coupler comprising: a firstduct-receiving portion for receiving an end of said first cable ductsection; a second duct-receiving portion for receiving an end of saidsecond cable duct section; a barb for securing said coupler to at leastone of said first and second cable duct sections, said barb extendingfrom a first end to a second end, at least one of said ends comprisingan edge positioned to engage a portion of at least one of said first andsecond cable duct sections when said first and second cable ductsections are positioned in said first and second duct-receivingportions; a cover overlying at least a portion of said barb, said covercomprising a fastener integral therewith for securing said barb to saidcoupler; and a mount positioned on said coupler, said mount defining anopening for receiving said fastener.
 2. The cable duct coupler of claim1, wherein said barb comprises a base portion and two arms, said armsbeing positioned at an angle relative to said base portion.
 3. The cableduct coupler of claim 1, wherein said barb comprises a plurality ofbarbs.
 4. The cable duct coupler of claim 1, wherein said fastenercomprises at least one detent.
 5. The cable duct coupler of claim 1,wherein said fastener is threaded.
 6. The cable duct coupler of claim 1,wherein said cover further comprises an aperture.
 7. The cable ductcoupler of claim 1, wherein said first and second cable duct sectionsare capable of being secured to said coupler without tools.
 8. A cableduct coupler for coupling a first cable duct section to a second cableduct section, said cable duct coupler comprising: a first duct-receivingportion for receiving an end of said first cable duct section; a secondduct-receiving portion for receiving an end of said second cable ductsection; a barb for securing said coupler to at least one of said firstand second cable duct sections, said barb extending from a first end toa second end, at least one of said ends comprising an edge positioned toengage a portion of at least one of said first and second cable ductsections when said first and second cable duct sections are positionedin said first and second duct-receiving portions; and a cover overlyingat least a portion of said barb, said cover defining an aperture forreceiving a fastener.
 9. The cable duct coupler of claim 8, wherein saidbarb comprises a base portion and two arms, said arms being positionedat an angle relative to said base portion.
 10. The cable duct coupler ofclaim 8, wherein said barb comprises a plurality of barbs.
 11. The cableduct coupler of claim 8, further comprising a fastener comprising atleast one detent for securing said barb to said coupler.
 12. The cableduct coupler of claim 8, further comprising a mount positioned on saidcoupler, said mount defining an opening for receiving said fastener. 13.The cable duct coupler of claim 8, wherein said first and second cableduct sections are capable of being secured to said coupler withouttools.
 14. A cable duct coupler for coupling a first cable duet sectionto a second cable duct section, said cable duct coupler comprising: afirst duct-receiving portion for receiving an end of said first cableduct section; a second duct-receiving portion for receiving an end ofsaid second cable duct section; a barb for securing said coupler to atleast one of said first and second cable duct sections, said barbextending from a first end to a second end and comprising at least onearm; a cover overlying at least a portion of said barb, said covercomprising a fastener integral therewith for securing said cover to saidcoupler; and a mount positioned on said coupler, said mount defining anopening for receiving said fastener of said cover.
 15. The cable ductcoupler of claim 14, wherein said barb comprises a base portion and twoarms, said arms being positioned at an angle relative to said baseportion.
 16. The cable duct coupler of claim 14, wherein said barbcomprises a plurality of barbs.
 17. The cable duct coupler of claim 14,wherein said fastener comprises at least one detent.
 18. The cable ductcoupler of claim 14, wherein said fastener is threaded.
 19. The cableduct coupler of claim 14, wherein said cover defines an aperture. 20.The cable duct coupler of claim 14, wherein said first and second cableduct sections are capable of being secured to said coupler withouttools.
 21. A cable duct coupler for coupling a first cable duct sectionto a second cable duct section, said cable duct coupler comprising: afirst duct-receiving portion for receiving an end of said first cableduet section; a second duct-receiving portion for receiving an end ofsaid second cable duct section; a barb for securing said coupler to atleast one of said first and second cable duct sections, said barbextending from a first end to a second end and comprising at least onearm; and a cover overlying at least a portion of said barb, said coverdefining an aperture for receiving a fastener.
 22. The cable duetcoupler of claim 21, wherein said barb comprises a base portion and twoarms, said arms being positioned at an angle relative to said baseportion.
 23. The cable duet coupler of claim 21, further comprising amount positioned on said coupler, said mount defining an opening forreceiving said fastener.
 24. The cable duct coupler of claim 21, furthercomprising a fastener for securing said barb to said coupler.
 25. Thecable duct coupler of claim 21, wherein said first and second cable ductsections are capable of being secured to said coupler without tools.